|The future perspectives of forestry in the P. R. of Croatia. pdf||1|
|A review of the investigations of Austrian Pine (Pinus nigra Arn.) and the application of their results in forestry. PDF EN||7|
|The share of assortments and the amount of wastes in the felling and rough conversion of Fir stems in the plant community of Abieto-Blechnetum. PDF EN||21|
|Summary: Discussed are the respective shares of assortments and wastes in the felling and primary conversion of Fir stems in the plant community of Blencho-Abietum, site class II, in the area of the Zalesina forest district in Gorski Kotar. Produced were: sawlogs, pitprops, pulpwood and fuelwood. At the cutting into assortments the decisive rôle was played by the dimensions and to a lesser extent by the quality. Wastes were not treated in a cumulative manner but according to the component parts (bark, excess measure for "nosing" logs for skidding, and the error of Huber´s formula). The waste for the notch in felling trees was neglected owing to its small size. From the losses due to the rounding off when measuring the diameters of sawlogs and mining timber presented were their upper and lower limits as well as the average value only in percentages.|
As to the measuring data in table 1 one can notice a correlation between the diameter b. h. on the one hand and the obtained assortments and wastes on the other. On the basis of this interrelationship the data were smoothed numerically by means of the correlation equations as follows:
a) sawlogs, bark and waste for "nosing" the logs by means of a standard straight line equation: y = ax + b;
b) pitprops, fuelwood and pulpwood, and the error of Huber´s formula by means of the equation: y = axb.
In these equations x represents the diameter b. h. over the bark, y the smoothed volume of assortments and wastes; a and b are the parameters of the equation.
The share of some assortments and wastes is directly proportional and of some of them inversely proportional with respect to the increase of d. b. h.
When using table 3 in practice in order to determine the percentage of assortments and wastes it is to be mentioned that the volume of the stands - to which the data are intended for application - ought to be established separately according to the diameter gradations. The data from table 3 are applicable only to the area from which the measuring data are derived, i. e. for the plant community of Blechno-Abietum, site class II.